The ongoing commercialization of digital data processing devices has generally resulted in mass storage capabilities being increasingly incorporated into a number of different types of devices, particularly with hand-held portable devices such as cell phones, digital cameras, personal data assistants (PDAs), etc. A disc drive is a type of mass storage device that generally stores data on one or more rotatable magnetic recording discs.
In operation, a corresponding array of data transducers is selectively moved across the surfaces of the discs to transduce data therewith. During periods of device use and non-use, portions of the head gimbal assembly (HGA) that includes the data transducers can inadvertently come into contact with the recording discs and cause damage that can lead to direct data loss and secondary reliability problems due to generated debris.
As portions of the HGA come into contact with a recording disc, any exposed edges can cause plastic deformation of both the HGA and the disc. However, such contact event is often undetectable due to low contact magnitude or no induced off-track motion.
As such, there is a continued need to improve contact detection regardless of magnitude or resulting motion. Therefore, it is desirable to detect any contact of an HGA, particularly with regard to contact events with small resultant deviations.